1. (Field of the Invention)
This invention relates to a toner seal method and apparatus of a photosensitive member cleaning device disposed inside an electrophotographic recording apparatus.
2. (Description of the Prior Art)
The principal mechanism and the outline of the operation of an electrophotographic recording apparatus will be explained with reference to FIG. 6. As a general construction, a developing device 2 is disposed on the right of a photosensitive member 1 and a photosensitive member cleaning device 3 is disposed on the left. A transfer electrode 4 for a recording sheet of paper (hereinafter referred to as "paper") and a separating electrode 5 adjacent to the former are disposed below the photosensitive member 1, so that, paper 6 passes above the transfer electrode 4 and the separating electrode 5 while keeping contact tangentially with the photosensitive member 1.
The photosensitive member 1 is rotated continuously in a direction represented by arrow by a main motor, not shown in the drawing, and is provided with a predetermined potential by a charging electrode 1a. A latent image is first formed on the photosensitive member 1 by exposure 15 and when it reaches the position of the developing device 2, a toner 12 inside the developing device attaches to the portion of the 1a tent image due to the electrostatic action with the photosensitive member 1, forming thereby a toner image 16. On the other hand, paper 6 is transferred to the lower surface of the photosensitive member 1 by a pair of conveyor rollers 7a disposed on a front transfer table 7 and the toner image 16 is transferred to this paper 6 by the potential of the transfer electrode 4. After the potential applied at the time of transfer is removed by the separating electrode 5, paper 6 is subsequently transferred to a rear transfer table 7b and then to a fixing device 13, where fixing treatment is carried out. Thereafter, paper is discharged outside the electrophotographic recording apparatus and the image recording process is complete.
After the transfer to paper 6 is complete, the photosensitive member 1 is separated from paper 6 and reaches the cleaning device 3, where the residual toner 12a attaching to the surface and residual toner 12a attaching to the surface and other foreign matters such as paper dust are removed by a blade 3a fitted to the cleaning device 3. A recovery casing 9 of the cleaning device 3 is equipped with a toner guide plate 11 made of a PET material and is shaped in a sealed type. Particularly, its blade end portion surface and the portion of the photosensitive member surface of the photosensitive member 1 are provided with a toner seal member in order to prevent invasion and scatter of the residual toner 12a and the paper dust that have been removed, into the electrophotographic recording apparatus.
The inventions and devices related with the technique described above are well known in the art and are disclosed in the following references. As to the end portion seal of the photosensitive member blade, the following references are known:
Japanese Patent Laid-Open No. 155877/1984 PA1 Japanese Utility Model Laid-Open No. 122970/1985 PA1 Japanese Patent Laid-Open No. 72470/1984 PA1 Japanese Patent Laid-Open No. 15274/1984 PA1 Japanese Utility Model Laid-Open No. 30760/1982 PA1 Japanese Utility Model Laid-Open No. 115274/1985 PA1 Japanese Patent Laid-Open No. 34580/1984 PA1 Japanese Utility Model Publication No. 12128/1985 PA1 Japanese Utility Model Laid-Open No. 16154/1985 PA1 Japanese Utility Model Laid-Open No. 159548/1983 PA1 Japanese Utility Model Laid-Open No. 121474/1986
As to the end portion seal of the blade, the following references are known:
As to the end portion seal of the toner guide plate, the following reference is known:
As to the end portion seal of the photosensitive member, the following references are known:
As to the photosensitive member surface seal at the end portion of the photosensitive member, the following reference is known:
After cleaned in the manner described above, the photosensitive member 1 rotates again to the position of the exposure 15 with a predetermined potential and then the first step of image recording is started. In this way, the steps of exposure to the photosensitive member 1, development, transfer, separation, cleaning and fixing of the image to paper 6 are carried out repeatedly and continuously and image recording to paper 6 is effected.
The photosensitive member cleaning device 3 is one of the important functions of the electrophotographic recording apparatus with the developing device 2 and the fixing device 13. The residual toner 12a and the paper dust that attaches to the surface of the photosensitive member 1 are removed and cleaned by the cleaning device 3 after transfer and the exposure 15 is made to this cleaned photosensitive member surface. Accordingly, a clear toner image 16 can be always obtained. However, the residual toner 12a and the paper dust that have thus been removed enter and scatter from the side surface of the blade 3a and near the photosensitive member surface at the end portion of the photosensitive member 1 into the electrophotographic recording apparatus. They attach to the charging electrode 1a, the transfer electrode 4 and the separating electrode 5, contaminate the surfaces of a mirror and a lens, invite non-uniform transfer, the drop of density and non-uniform density that are detrimental to the recorded image and further cause troubles such as transfer jam of paper 6 due to incomplete separation. The frequency of the maintenance work must be increased in order to prevent these troubles and the economical loss is great.
Various inventions and devices have been developed conventionally as described already by disposing the toner seal member inside the cleaning device 3 in order to eliminate the problems described above. Though they provide a certain level of effects, none of them are entirely satisfactory. In other words, they divide, cut and patch up function-wise a flexible member such as a Moltopren, velvet or woolen cloth in such a manner as to come into contact with the photosensitive member surface, the blade end surface and the end surface of the toner guide plate, and the complicated and fine work relies exclusively on the skill of an assembling person. Accordingly, uniformity and reliability in mass-production are not yet complete.